Device for removing plaster casts or bandages



J. M. EERHARD ET AL 2,220,223

Filed Oct. 26, 1957 2 Sheets-Sheet 1 FIG mvENToR, JOHANNES M. EERHARD L E w 1 D N A A A 5 J .5 RM EE N SR Ao CC Nov. 5, 1940.

DEVICE FOR REMOVING PLASTER GASTS 0R BANDAGES Nov. 5, 1940. J. M. EERHARD El AL DEVICE FQR REMOVING PLASTER CASTS 0R BANDAGES Filed Oct. 26, 1937 2 Sheets-Sheet 2 M'W M ATTYS.

Patented Nov. 5, 1940 UNITED STATES PATENT OFFICE,

DEVICE FOR nnMovmo PLASTER CASTS v on BANDAGES Application October 26, 1937, Serial No..171,146 In the Netherlands October 29, 1936 7Claims.

The inventionis concerned with a device for cutting or chipping away plaster bandages or plaster casts, of the type including a motor-actuated' punch or chisel which is adapted to cooperate with a spoon or anvil inserted between the plaster bandage or cast and the part of the body encased by the latter.

It is an object of the invention to improve the known devices of this kind, and the, im-

lO proved apparatus according to the invention can be more readily operated, and when using the apparatus the bandage or cast can be cut or broken away without the patient being hurt in any way. Moreover, the device according to the invention has the further advantage that it can be satisfactorily adapted to the shape of the body and the cutting away of bandages or casts which follow parts of very pronounced curvature occasions no difficulty.

A rapid operation is, moreover, possible and the portions of the plaster cut away are conducted away in. a simple and eifective manner. The device according to this invention also has the advantage that itsuse does not involve the production of dust, and this must be regarded as an improvement of considerable importance having regard to the conditions under which the apparatus has to be employed.

According to the present invention, therefore, we provide an apparatus for removing plaster casts or bandages including a motor-actuated punch or chisel, a co-operating anvil or spoon which is adapted to be inserted between the body and the bandage or cast, and a connection as piece between the anvil and the main body of the apparatus, said punch orchiselhaylng its lower portion of U or channel form in cross section with the open side of the U facing said connection piece. Y

According to another feature of the invention the apparatus includes a connection piece supporting the anvil or spoon on the apparatus, the punch or chisel having its lower portion of U or channel shape in cross-section and having its open side facing in a direction opposite to that in which the apparatus will travel during the cutting of the cast or bandage.

' Each upward and downward reciprocating stroke of the chisel produces an impact which 50 cuts away a small section of the plaster havinga width corresponding to the width of the opening of the U in the chisel cross section.

According to anotherfeature of the invention, means are provided for enabling the pieces of plaster to be borne away through the chisel or punch itself, if made hollow, directly after they have been severed or broken away. To this end the upper portion of the chisel or punch may be of U-fornr with the open side of the U facing away from the connecting piece by means of which the anvil is secured to the remainder of the apparatus.

According to another feature of the invention the chisel or punch has an obliquely-disposed passage therethrough, such passage opening at its lower end at the foot or cutting edge of the chisel or punch and at one side of the latter adjacent said foot or cutting edge, and opening at its upper end at the, other side of the chisel or punch.

Another feature of the invention lies in mak-: ing the distance between the outer walls of the limbs of the ,U smallest in the neighbourhood of the cutting edge. Consequently the slot through the punch or chisel is simultaneously somewhat constricted. The cutting away of a bandage which follows a line of pronounced curvature is thereby facilitated.

To ensure an accurate positioning and guiding of the punch or chisel, the latter is provided by 25 the present invention with guiding cheeks or lugs located between the anvil and the main body of the apparatus and on both sides of the connecting piece.

In order to centre the punch in anabsolutely 3o accurate fashion a chisel-like guiding body may be furnished between the guiding cheeks'or lugs and arranged to slide in a guiding slot in the connection piece.

With the apparatus described above, it is possible that pieces of material or plaster severed from the bandage or cast might congregate at the lower end of the guiding slot and consequently interfere with the operation of the punch or chisel. To prevent this, in another feature of the invention the downwardly-directed cutting edge of the chisel-like guide body referred to in the preceding paragraph is made to cooperate with a second cutting edge in the lower end 01' the guide slot. By this means any materials collecting in the slot will be cut or smashed up when the punch performs its downward stroke and will thus be prevented from causing jamming or interferen'ce with the guiding action.

Further advantageous features of the invention will be disclosed by the ensuing description, which refers to the accompanying drawings wherein one embodiment of the invention has been illustrated by way of example.

In these drawings:

Figure 1 is a side view of a device according to the invention,

Figure 2 is a longitudinal section on 11-11 of Fig. 1 and is drawn on an enlarged scale,

Figure 3 is a front elevation of the same device with a part shown in section on III-III of Fig. 1,

Figure 4 is a section on the line IVIV of Fig. 3, showing the punch or chisel in its lowest position, and also theanvil, and

Figure 5 is a section on V-V of Fig. 4 viewed in the direction of the arrow,

Figure 6 is a face view of the actuating cam.

Referring to the drawings, the ramming tool,

which is here a chisel or punch of hollow form,

is depicted by the numeral l and 2 is the electric motor which actuates this punch through the intermediary of the operating mechanism 3. The motor may be of any desired type and adapted for connection to the local current mains.

The punch l co-operates with a small anvil or spoon 4 which, when the device is in 'use, is pushed under the bandage or cast and at the same time acts as a guard since it prevents injury of the part of the body around which the bandage is wound.

The anvil 4 is attached to the casing 5 of the actuating mechanism by a connection piece or bracket 6 (see Figs. 1, 3 and 4) which is provided with a guide slot 1 extending parallel to the medial line of the plunger. A guide block 8 is movable in the slot 1 and is arranged between a pair of lugs 9 projecting laterally from the lower part of the punch'or chisel. A cutting edge i0 is provided at the lower end of the guide block for cutting or breaking up small portions of the bandage material, plaster and so on, which may accumulate in the slot 1 during the use of the device. Co-operating with this cutting edge is a corresponding fixed cutting edge 44 in the lower end of the guide slot 1.

The upper part of the anvil 4 slopes upwardly to a certain extent in the direction of the slot 1, whereby this anvil can be pushed between the bandage and the body like a wedge. At the part c remote from the guideway 1, the lower end of the punch I has a sharp angle whereby the material to be broken through more readily yields to the punching action.

Fig. 4 clearly illustrates the construction of the punch or chisel. A horizontal section through the lower end of the punch will be of U-shape. If the section is taken higher up, however, the shorter side of the U disappears and at sections still higher it moves to the other side of the limbs. In this way the channel 43, referred-to above, is formed and serves the purpose of receiving and disposing of ,the small strips or splinters smashed or cut from the bandage.

At its upper end the punch I is pivotally connected to an extension II which moves in a hollow cylindrical part l2 of the casing 5. The upper end of the extended portion l I is formed with a reinforced head l3 which fits and is guided inside the part 12, and is provided at the top part with a roller M. This roller is pressed against the periphery of a curved disc or cam l5 by a spring I6 which continually urges the ram or punch into its uppermost position.

The cam or disc i5 is rotatable about a pivot I! in the casing 5 and is rotated by the electric motor 2 through a transmission gearing comprising a worm wheel l9 and a worm [8 which constitutes an extension of the shaft of the motor 2. A toothed wheel 2| is also located on the shaft 20 of the worm wheel and co-operates with a second gear wheel 22 arranged on the same pivot IT as the disc or cam l5. The shafts of all these gear wheels are mounted in recesses in the casing 5 of the actuating mechanism, which casing is advantageously filled with oil or a lubricating material of similar consistency.

The curved outline of the cam i5 is so selected that when the cam is rotated the roller I4, and consequently the punch l, are moved downwards against the action of the spring IS with a uniform speed, and when a predetermined point in each rotation is reached, the punch moves rapidly back to its uppermost position under the influence of said spring.

A clip 24 is fastened to the bracket 6 carrying the anvil by means of screw bolts 23, and this clip passes around the lower part of the cylindrical extension l2 of the casing 5 and bears at its upper part against a collar 25 on said extension. When the clip 24 has been turned in relation to casing 5 into the desired angular position it canbe clamped rigidly in place by means of a wing-nut 26. The clip 24 is held at the lower end of the part I2 by means of a. screw threaded washer 27 which is screwed on a corresponding thread on the part 12 and is, in turn, positioned by a counter nut 28.

A packing bush comprising an inner fixed ring 29 and an outer screw-threaded ring 30 is provided at the place where the extension ll of the punch I leaves the casing l2. The opening on the ring 29 for the passage of the part i l is provided, at the part where the guide surface 3| is located, with a straight edge.

The ability of the two parts I and l l to rotate relatively one to the other is achieved in the following fashion:

A pin ,32 is inserted in the lower end of the part I l and has a head 33 of smaller diameter projecting beyond this part I I and into a cup-shaped recess 34 in the upper end of punch I (see Fig. 4). A ring 35 is screwed into this hollow chamber 34 and fits around the head 33, being rotatable relative thereto. The ring 35 is held in place by a washer 36 and a riveted head 31. Rotation of ring 35 relatively to the punch is prevented by pins 38. I

The apparatus is further provided with two handles, one of which is the stirrup-shape handle motor housing. A press button contact 4! is arranged in the loop of the stirrup and enables the user to make or break the supply of current to the motor. The other handle, 42, is in the form of a peg and is parallel to the shaft of the electric motor. g

The device as above described functions in the following fashion:

The roller I4 is pressed by the helical spring l6 (Fig. 3) which bears on the reinforced head I 3 of the extension ll of the punch, against the periphery of the cam l5. Consequently the punch j or chisel will at all times be maintained by this I4 is released from the cam and jumps upwards as a consequence of which the punch suddenly moves upwards. This procedure is repeated at a comparatively rapid rate.

Each time the punch reaches its lowest position in relation to the anvil 4, the portion of the plaster bandage or cast between these two parts is severed or smashed into thin splinters which collect in the space 43 of the punch and in this way are removed.

What we claim is:

1. Apparatus for removing plaster casts including a motor-actuated chisel, a co-operating anvil which is adapted to be inserted between the body and the cast, and a connection piece between the anvil and the main body of the apparatus, said chisel having its lower portion of U form in cross-section with the open side of the U facing said'connection piece.

2. Apparatus for removing plaster casts including in combination a motor-actuated chisel, a co-operating anvil which is adapted to be in.- serted between the body and the cast, and a connection piece supporting said anvil on the apparatus, such chisel having its lower portion of channel shape in crosssection and having its open side facing in a direction opposite to that in which the apparatus will travel during the cutting of the cast.

3. Apparatus for removing plaster casts including a motor-actuated chisel and a co-operating anvil which is connected to the main body of the apparatus and is arranged for insertion between the body and the cast, said chisel having an obliquely-disposed passage therethrough, such passage opening at its lower end at the foot of the chisel and at one side of the latter adjacent said foot, and opening at its upper end at the other side of the chisel.

4. Apparatus for removing plaster casts including a motor-actuated chisel, a cooperating anvil adapted to be inserted between the body and the cast, and a connection piece between the anvil and the main body of the apparatus, said chisel having its lower portion of channel form in cross-section with the open side of the channel facing said connection piece, the upper portion of the chisel being of U form, with the open side of the U facing away from said connectio piece.

5.'Apparatus for removing plaster casts including a motor-actuated chisel, a cooperating anvil adapted to be inserted'between the body and cast, a connection piece between the anvil and the main body of the apparatus, said chisel having its lower portion of channel form in crosssection with the open side of the channel facing said connection piece, and a pair of guide cheeks provided on the chisel and located one on each side of the said connection piece.

6. Apparatus for removing plaster casts including a motor-actuated chisel, acooperating anvil adapted to be inserted between the body and the cast, a connection piece between the anvil and the main body of the apparatus, said chisel having its lower portion of channel form-in cross-section with the open side of the channel facing said connection piece, a pair of guire cheeks provided on the chisel and located one on each'side of the said connection piece, and a chisel-like guiding member provided between the cheeks and arranged to move-in a guiding slot in said connection piece the. downwardly directed cutting edge of the guiding member being adapted to cooperate with a second cutting edge in the lower end of the guiding slot.

7. Apparatus for removing plaster casts including a motor-actuated chisel having a cutting edge at its lower portion, a cooperating an- 

